1. Field Of the Invention
This invention relates to a filter and more particularly to a support for the resonant cavity of a band pass-band reject filter.
Band pass-band reject filters are well-known filters which are used to limit the frequencies which are available to a circuit. Typically, they comprise tuning elements so that the particular pass and reject frequencies can be varied.
The filter elements may be contained in a housing which comprises a resonant cavity for the filter. Usually the filter or a plurality of filters are supported by a plate which is mounted on an instrument rack or the like. Typical filters are manufactured by Wacom Products, Inc. of Waco, Tex., and Celware of Marlboro, N.J. The Wacom filter is described in U.S. Pat. No. 4,080,601 to Alcorn.
Band pass-band reject filters must be carefully adjusted and aligned to exhibit the desired characteristics. Thus, if they are struck or dropped, then they can easily fall into disalignment. This is a problem during assembly and shipping. It also is a problem after the filters are mounted on an instrument rack since they can be jarred by personnel or by being struck by other devices which are being mounted or removed from the instrument rack.
With the foregoing in mind, it is desirable to have the resonant cavity of a band pass-band reject filter be of sufficient rigidity so that it will be able to resist the type of jarring and subsequent misalignments described above.
Preferably, the structure which accomplishes this result should be such that it can support more than one band pass-band reject filter.